In Paris, many museums are free on the first Sunday of each month. Thus the lines for museum entry can be extremely long. Is it possible to skip through the line if I bought a ticket in advance?

I ask because the security line to enter the Louvre is usually quite long and visitors who pre-purchased tickets can skip to the front of the security line, so I'm wondering if this applies on free-entry days (as it can be worth my money to save time in the line).

Almost everyone reports that even if you get in quickly, it depends what you're after. You may be in a MOB of people trying to see the Mona Lisa, or if you have other tastes, one for example reports being alone in the 18th century Scandinavian art room on a free Sunday.

From all reports, unless you are prepared to get there really early, and accept that there may be mobs of families and screaming children (especially if it's a wet day outside), try to go during the week instead. The fee you pay will be worth it, and then you can use one of the skip-the-queue options with your ticket.